1. Field of the Invention
The present invention relates to an armature core of a start motor, and in particular to an armature core of a start motor in which the depth of a slot in which an insulation member installed in a core is overlapped is deeper than other insulation members by 1.5 through 2.5 times compared to the thickness of an insulation member, and the width of the slot is the same as that of the other slots.
2. Description of the Background Art
Generally, in order to rotate a pinion, an armature is installed in a start engine which is capable of starting an engine of a vehicle. The armature is formed of a plurality of cores overlapped. The slots on which a coil is wound are radially formed in the core.
As shown in FIG. 1, a conventional core 1 of a start-motor armature 10 (FIG. 3) is formed of one insulation member overlapping slot 3, in which a front end 5a and a rear end 5b of the insulation member 5 are overlapped, and a slot 2 having a certain width and depth. The insulation member overlapping slot 3 has a width wider than the thickness t of the insulation member 5 compared to the other slots 2.
Namely, the above slots are formed in such a manner that the width xe2x80x9caxe2x80x9d of the overlapping slot 3 is smaller than the width xe2x80x9cbxe2x80x9d of the other slot 2(a greater than b). A coil is wound onto the slot. The slots are installed so that the overlapping portion of the insulation member is not escaped by the coil.
However, in the conventional art, the width of one overlapping slot is wider than the width of the other slot for an overlapping portion of the insulation member. Therefore, the widths of both sides of the slot having a wider slot becomes narrow. As the width is decreased, the strength of the portion in which the width is decreased is weak compared to the other portions. Therefore, when winding the coil onto the slot, the portion in which the width is decreased may be transformed. The winding state of the coil is bad. The performance of the start motor is decreased.
Accordingly, it is an object of the present invention to provide an armature core of a start motor in which the depth of a singular slot in which an insulation member installed in a core is overlapped is deeper than the depth of other slots by 1.5 through 2.5 times the thickness of the insulation member, and the width of the singular slot is the same as that of the other slots.
In order to achieve the above object, there is provided an armature core of a start motor in which a width xe2x80x9caxe2x80x9d of the insulation overlapping slot and a width xe2x80x9cbxe2x80x9d of other slot are same, and a depth xe2x80x9cAxe2x80x9d of the overlapping slot is 1.5 through 2.5 times of a thickness of the insulation member compared to a depth xe2x80x9cBxe2x80x9d of the slot, and a groove is formed at an entrance portion of the slot in a structure that a front end and rear end of an insulation member are overlapped and inserted in an armature core of a start motor, and one insulation member overlapping slot and a plurality of slots each having a certain width and depth are radially formed.